The Vedas are supreme among the various forms of knowledge and Vedas have to be learnt and understood for their own sake without expecting any reward. That is why our ancients had thought best to utilize various portions of the Veda Mantras for purpose of rituals and ceremonies for conferring spiritual as well as material benefits on mankind since they knew that very few people would learn Vedas merely for their own sake in these days.
The word Shiva is considered by the sages as Jivaratna or the Jewel of life. That life jewel praised by all the Vedas and also called Shankara, form, Tryambaka etc. , is the only refuge for all living beings and gives all happiness in life. To worship such an income from, all devotees of Shiva used to observe the following five rules. (1)Rudraksha Dharanam; (2)Bhasma Dharanam in the prescribed manner ; (3) Panchakshara Mantra Japaby those who have been initiated by a Guru or Shiva Nama Japa by those not initiated into Mantra, (4) Performing daily Panchayatana Puja and (5) Meditating constantly on Sadashiva.
Ancient Sages have prescribed several ceremonies and austerities where Vedic Mantras are used for worship. One of such Mantras of high potency and power is called SRI RUDRAM of Taitriya Samhita of Sri Krishna Yajurveda. Samhita consists of seven ‘cantos’ containing 44 Chapters of ‘Prasnas’ . In the middle of the 4th Canto of this Samhita ‘ SRI RUDRAM’ is the fifth chapter. This chapter is divided into 11 ‘Anuvakas’ or paragraphs. It is a prayer to Lord Shiva praising His various attributes and qualities.The importance of Sri Rudram is that it occurs in the middle of the Taittiriya Samhita and in the central portion of Sri Rudram is to be found the greatest of the Mantras viz. THE PANCHAKSHARA MANTRA. Sri Rudram is, therefore, the holiest of holy Mantras. It is also called Namaka Prasnam as the word NAMAH occurs several times. It is also known as Shatharudriyam. It is recited not only for one’s own purification and attainment of higher spiritual knowledge but also for bringing welfare to oneself and to the country as a whole.
Traditionally, the seventh chapter of the 4th Cantos of Taittriya Samhita called the CHAMAKA Prasnam is also recited along with Sri Rudram Prasnam in which there is a prayer for seeking material benefits ranging from material needs such as food to eat , to achieve ultimate salvation . Constant repetition of Rudra mantras in the prescribed manner is called JAPA YAGNA . This Japa Yagna is followed by Abhishek, Hawan, and Archana to Lord Shiva by which the efficancy of Japa yagna is enchanced .
Sri rudram japam is normally done after an elaborate Anganyasa which is called MAHANYASA . Sri Rudram is then chanted eleven times and at the end , one Anuvaka of Chamaka Prasnam is chanted . Thus when Sri Rudram is chanted 11 times, Chamakam is chanted once in full ; i,e., the first eleven anuvakas of the seventh prasna of the 4th canto of Taitriya Samhita. Simultaneously , Abhishekam is also performed on a ‘Shivalinga’ chanting Sri rudra eleven times and Chamaka once. The significance is that ,the eleven forms of Lord Shiva viz: Mahadeva, Shiva, Rudra, Shankara, Neelalohita, Eashana, Vijaya, Bhima, Devadeva, Bhavodhbhava and Adtiiyatmaka Rudra,are invoked in eleven Kalasas (kumbham) when eleven Pundits chant Sri Rudra Mantra eleven times each according to the above procedure followed by one anuvaka of Chamaka . Then Hawan is performed chanting Rudra and Chamaka prasana in full and pouring pure cow’s ghee into the fire in one unbroken stream chanting Chamaka Prasna called VASORDHARA . Abhishekam is also performed with the water sanctified in the eleven Kumbhams to the lord while the same is also sprinkled on all the devotees assembled to witness the Maharudra Yagna. Then Archana is performed with flowers and ‘Bilwa’ leaves with various Mantras . The Yagna is then concluded with Managala Arti and Mantra pushpanjali .
In the Rudrikadasini, as it is called, Sri Rudra Mantra is chanted 121 times by the 11 pandits each chanting 11 times and the chamaka mantra is chanted 11 times, each pandit chanting once in addition to the chant required for Abhisheka, Archana, and Hawan . Eleven such (RUDRIKADASINIS) are required to be performed for a (MAHA RUDRA YAGNA);i.e., 11 pandits duly initiated and trained in Vedas and knowing the various Mantras required for chanting according to proper Swaras. At the time of Rudra Japa , there should be purity in all the three Karanas- Mano, Vak, and Kaya – Mind, speech, and body . The Maharudram is usually done for 11 days but to save time depending on local conditions , it may be done in 4 or 5 days according to the availability of pandits, time and resources . Alternatively , 11 groups (GHANAS) of 11 Vedic Pandits each can conduct the Maharudra Yagna in one day also , each group performing one (RUDRIKASASINI).
Eleven Such Maharudra Yagna performed without break i.e., 121 Rudrikadasinis will be required for one ATI RUDRA MAHA YAGNA. These 12 1 Rudrikadasinis can be performed by 121 Vedic Pandits for eleven days consecutively or 11 Vedic Pandits consecutively for 121 days.
What is important is the total number of times the Rudra mantras are chanted accompanied by the Chamaka Mantras. The number of days and the number of Pandits may be modified according to convenience . But this modification has to be done only according to the prescribed procedure so that the essentials are not left out.